1. Field of the Invention
Embodiments of the present general inventive concept relate to a discharging circuit, an electronic apparatus or an image forming apparatus having the discharging circuit, and a power supply unit to reduce a standby power.
2. Description of the Related Art
For energy saving from the viewpoint of the protection of the environment, standby power restriction of electronic appliances has been strongly carried out not only by domestic stages but also by American (EPA 1.2) and European (ErP Stage 2) stages. In order to overcome the above-mentioned standby power restriction problem, various efforts for reducing standby power of electronic appliances have been conducted.
An electromagnetic interference (EMI) filter for eliminating noise may be installed at an input terminal of the power supply apparatus (for example, SMPS). Charges of X-capacitor installed at the EMI filter may flow in a metal terminal of a plug when the plug is turned off, causing a safety problem. Therefore, a discharge resistor for discharging electric charges charged in the X-capacitor may be useable to resolve the above problem. However, since a power loss occurs in a standby mode due to the discharge resistor, this is a retrograde step for efforts to reduce standby power of electronic appliances, such that a countermeasure against the above-mentioned problem is needed.